In case you have issues with your SSO, then you can bypass SSO using the URL, https://domain.freshservice.com/login/normal. When you hit the URL, you will be taken to the login page where you will have to enter your local Freshservice credentials.
For Freshworks accounts, you can use https://domain.freshworks.com/login/normal to bypass the SSO and until the issue with the SSO is sorted.
Note that the bypass on Freshworks Org enabled accounts is only possible for users with the Organizational admin permissions.
You can enable the native login credentials at Helpdesk security for other users to workaround this issue temporarily